Answer
ON DELETE CASCADE makes deletion of a referenced row delete its matching referencing rows. • The action is declared on a foreign key. • It is appropriate when child rows cannot exist without the parent. • It can remove many rows, so the relationship and permissions must be reviewed carefully.
💡 SQL Example
FOREIGN KEY (order_id) REFERENCES orders(order_id) ON DELETE CASCADE
Result
Deleting an order also deletes its dependent rows
⚡ Quick Revision
Cascade delete automatically removes dependent foreign-key rows.